1. Field of the Invention
This invention relates to a novel non-flammable composite materials and to methods for producing the same. More particularly, this invention is concerned with non-flammable composite materials for application to fibers, plastics, film and other shaped products. The invention pertains to compositions containing at least one of the inorganic compounds with phosphorus and nitrogen, or either of them.
2. Description of the Prior Art
Since two decades before, many products from a petroleum have developed remarkably and innumerable kinds of plastics, synthetic fibers, resins and films have become very popular, and actually these have become to be daily necessities.
The products made from petroleum possess many excellent characteristic features which are unable to be expected for natural products. Therefore, utilizations of the products made from petroleum have developed rapidly especially these recent years. However, products originated from petroleum have a big common defect, namely, easy-flammability. From users, appearances of non-flammable or self-extinguishable materials have long been very anxious, especially for interior materials, fibers for industrial and clothing uses and for architectural things, because there has been pointed out the high possibilities to induce a big disaster caused by the presence of an easy-flammable materials. Actually, many cases of this kind have been reported so far.
Therefore, an addition of non-flammability or self-extinguishable properties to the products is now one of the most urgent problems to be solved, and for this purpose, world-wide researches are now intensively going on. However, the products were made originally from petroleum which is liable to flame, and hence there has been only little success in giving a non-flammability or self-extinguishable property to the products.
Non-flammable fibers are most urgently required, because fibers are now used all over the places and homes, and most of the miserable fire-disasters were due to the presence of easy-flammable fibers. Unfortunately, in spite of many intensive studies, there has been very little useful accomplished in the way for the addition of non-flammability to fibers.
For example, for acrylic fibers, copolymers comprising of acrylonitrile and halogen containing monomers such as vinyl bromide or vinyl chloride were used. But when this copolymer was used for the preparasion of an acrylic fiber, its effect was not satisfactory. In order to give a sufficient flame retardant or self-extinguishable property, more than 10% of vinyl bromide should be incorporated, nevertheless, the effect was still very unsatisfactory. Together with a big cost-up by using large amounts of this expensive monomer, physical and tensile properties of the fiber were reduced considerably as the amounts of incorporated vinyl bromide increased. In additon to this, these copolymer gave poor processability in shaping processes. Also the copolymer effects discoloration.
This also reduced the quality of the fiber, accordingly, reduced the commercial values of the fiber. Furthermore, even if the copolymer could give an appreciable flame retardant properties to some extent, it is still unsatisfactory, and when the fiber are ignited, toxic gases such as bromine gas or hydrogen bromide gas are usually developed. These will increase a disaster remarkably.